SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '218bda232c2904e815b3a14833aacddb3a7888325dbb8d48abb5909ceb021396' 
  AND token = 'JzyqOrhfMitgEYtVJHbnahtQCnz0AsRT5/qzcYrNhuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}