SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3db49ce9e852cd522a629321b1789440f01b176b3a63478a7a11cb21ee2cf5d3' 
  AND token = 'kNSMx1gfK7ziIJZPNilsKY7ZsJ9biNzwrIKGBPkHpek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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