SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f20dfa0aaab6544c3b0411a6aff79c665aa78455d80d67bea4ce584a5b9097fd' 
  AND token = 'MNr9CkhpPnh48l72y08SL9VEuOBwcoLSii4Kt37VMok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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