SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f65555951052e96573cef7fa5f3262c526b828c4dface21814af5729a01b77b4' 
  AND token = '6ZA3PkD7AMfvCPb3RoJhPUFFAcnHoxfYeF9Lb9rAWrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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