SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae00a0483aa8a68594ab2430ddc2bf44eea497a3e18dc7bc5794798f13ed4d5e' 
  AND token = 'jeJhh4jA3EVysrjY33QxQ8OKXyEykYDGg2F6PT//MiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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