SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea08ff8f266b2c2af2987c074c8109255f7fad6857fa2595a7943720ab25873f' 
  AND token = 'KRaF6yfsvYfG4BFPVhnzCPxwrgwGKHiRFluhnmVTpa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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