SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c0dd7a028066050c42d2896361f494732c3cf6014286edce40d2c8808ae88eb' 
  AND token = 'wC6GCkfrSCSV8R/Q4bCrXpL1YCoxU2nt0j10yD1bQUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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