SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6494a3c64dfde69c5ef93dd146118e060b55ca653183c9787689675e0638d54b' 
  AND token = 'fChengSWRSHbYopRNtPISoF3BZyXsBVFYQBqT44CkRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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