SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cff1c66e4315da26eeaaf6be5e00c0a767991580890615c1bd61ce33b25d860' 
  AND token = 'Y2aO+g0pctnEnZG7kGyFLlXW6eHC6G7977Dkiv13EL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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