SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1744ea55bdb18f2b8d292e554c8d9fdcf40cdb8192255b31294de6916b123bfe' 
  AND token = 'zgdap6x0RWGCe6gj2wc9FW0sOQ6BL+DYFFbcuHkPGu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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