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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3d719dfd85cb8ff5b8663acef7aff8bc2340c4c8a6cc8947a957a2333f3eb4c' 
  AND token = 'NtyfHR5LQp06PEbdVQy1n8U05P0GHk0e+ZElj1HfduM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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