SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc9fdc4d6f65f23d31d9b2d3c44b0f061c7409c515581f7c6a875f185668ac4b' 
  AND token = 'ztwXOJMI7oRLlB1laFa31/Djn3Tma3VVaPg7pqRQG2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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