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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3a5927857842e6d4b58c7eefef2d6b5ab49e655ca1807545e2ccd40c8f86a1c0' 
  AND token = 'WSBqDZctNloGiSir+f4hyYFRmyk3IgJ4p4cANv0NOrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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