SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1593d141782146610b8d9874167296d07af1d62c1a1ce5e2d8df8c323a94e2dd' 
  AND token = 'wwPsqiuAzHvpDRyB5NoVyv6XpgllqS/0ooujdzbBrg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}