SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b38a009cc6d59a884f0003cce49fc03c3bd3ae7a0a7c01732fac6694cf44dd79' 
  AND token = 'P0lhPXD/6HqGgNkegVuvHIV/2CsbcjnkIzETp2eayuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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