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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e8ed3f79be987e8f0a390eebb00f6a1bcb2ee35a5e13bd447f8e5083ef56997f' 
  AND token = 'CvUqiC4WGUDRtzmDVw03mzDiXWnxsrAjfm9qRAFc6L8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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